JPH03217078A - Surface treatment of internal-layer base material for multilayer copper-clad laminated board - Google Patents

Abstract

PURPOSE:To enable a surface treatment film to be formed uniformly on an internal-layer base surface for stabilizing and improving adhesion force with the internal-layer base material of a multilayer substrate and for enhancing the reliability by performing surface treatment of the internal-layer base material by using a surface treatment liquid which is obtained by mixing an interface activator where a specific amount of interface activator is mixed into a surface treatment liquid including a specific amount of coupling agent. CONSTITUTION:In a method for performing surface treatment onto an oxidized film surface of a copper foil of an internal-layer base material for forming a multilayer copper-clad laminated board, surface treatment of the internal-layer base material is performed and a surface treatment film is formed by using an interface activator mixed surface treatment liquid which is obtained by mixing a 0.05-3wt.% interface activator into a surface treatment liquid which includes 0.3-5wt.% coupling agent. For example, a surface treatment liquid including an interface activator where a 0.05wt.% fluorine interface activator is added to a coupling treatment liquid (beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane 2wt.%, an acetic acid 0.5wt.%, an ethanol 60wt.%, a water 37.5wt.%) is used as a surface treatment process g for dipping the internal-layer base material where patterning and an oxide film are formed. After that, the surface treatment film is formed after drying at room temperature and further drying h at 110 deg.C.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for surface treatment of an inner layer base material of a multilayer copper-clad laminate using an insulating material such as an epoxy resin, and particularly relates to a surface treatment method for an inner layer base material of a multilayer copper clad laminate using an insulating material such as an epoxy resin. The present invention relates to a surface treatment method for improving the adhesion between an oxidized surface of copper foil and a resin layer.

[Conventional technology]

In recent years, requirements for the various properties of copper-clad laminates have become increasingly strict. This tendency is particularly noticeable in copper-clad laminates for industrial and consumer printed wiring boards. For example, due to the demand for higher density, signal lines are becoming thinner and thinner.
Adhesion strength between the copper foil and resin is important to ensure reliability. In addition, there is a remarkable trend toward multilayering, and the adhesive strength of copper foil is becoming more important not only between the roughened surface of the copper foil, but also between the shiny surface of the copper foil and the resin layer that adheres to it.

FIG. 2 is a system diagram showing the manufacturing process of a multilayer copper-clad laminate, which includes the manufacturing process of a multilayer board after manufacturing the inner layer base material.

Generally, the inner layer base material is 0.5 to 0. A double-sided copper-clad laminate with a thickness of about 6 mm is used. After patterning (a) on the copper foil on both sides by etching etc. to form a predetermined circuit pattern, the surface is leveled (b) and washed with water (C). )
, drying (d). and oxidation treatment step (e
), the copper foil circuit pattern is oxidized to form an oxide film on the surface, and then dried (f). Thereafter, in the surface treatment step (g), surface treatment is performed using a coupling treatment solution that generally contains a campling agent, and after passing through the drying step (h), the multilayer substrate manufacturing step (i) is performed. In the multilayer board manufacturing process (i), a surface-treated inner layer base material, prepreg made of glass cloth-epoxy resin and hair are alternately laminated, and copper foil is laminated on the outermost layer and then heated and pressure molded. Manufactures multilayer copper-clad laminates.

FIG. 1 is a cross-sectional view showing the surface treatment apparatus. In the figure, (1) is the inner layer base material, (2) is the copper foil circuit pattern laminated on both sides thereof, (3) is the surface treatment liquid, ( 4) is a processing liquid layer.

The conventional surface treatment method for the inner layer base material (1) is to use a surface treatment liquid (3) consisting of a coupling treatment liquid containing a coupling agent.
is placed in a treatment liquid tank (4), and the inner layer base material (1) on which the circuit pattern (2) is formed, which is the material to be treated, is immersed therein, then pulled up and dried, and the surface treated film is placed on the inner layer base material. Formed on the surface of material (1). After drying, the inner layer base material (1) is subjected to the next multilayer board manufacturing process.

[Problem to be solved by the invention]

3 However, in the conventional surface treatment method as described above, the inner layer base material (1), which is the material to be treated, is simply immersed in a surface treatment liquid (3) containing a coupling agent, and then pulled up and dried. Therefore, regardless of the viscosity or composition of the surface treatment liquid, there are parts on the surface of the inner layer base material (1) where the copper foil circuit pattern (2) is formed and parts where it is not formed. Therefore, a uniform surface treatment film cannot be uniformly formed on the surface of the inner layer base material. For this reason, during the multilayer board manufacturing process, blistering and peeling may occur between the surface treatment film and the resin layer that adheres to it, significant variations in adhesive strength may occur in the multilayer board after manufacturing, and blistering and peeling may occur due to solder during mounting. There was a problem in that reliability was significantly impaired.

Conventionally, surface treatment liquids have a viscosity similar to that of water or solvents, and surface treatment films are colorless and transparent, and their thickness is extremely thin, so the relationship between the adhesion state of the surface treatment film and its adhesive strength has not been sufficiently studied. Ta.

The present invention has been made in order to solve the above-mentioned problems, and it forms a surface treatment film uniformly on the surface of the inner layer base material to stabilize the adhesive force with the inner layer base material of the multilayer substrate. The purpose of the present invention is to propose a surface treatment method for an inner layer base material for a multilayer copper-clad laminate, which can improve the reliability of the inner layer substrate.

[Means to solve the problem]

The method for surface treatment of an inner layer base material for a multilayer copper-clad laminate of the present invention includes:
In a method of surface-treating the surface of an oxide film of copper foil as an inner layer base material for forming a multilayer copper-clad laminate, 0.0% of a surfactant is added to a surface treatment solution containing 0.3 to 5% by weight of a coupling agent.
．． In this method, the inner layer base material is surface treated using a surface treatment liquid containing a surfactant mixed in an amount of 05 to 3% by weight to form a surface treatment film.

Examples of the coupling agent for the surface treatment liquid used in the present invention include a silane coupling agent, a titanium coupling agent, and a mixed coupling agent of both. In addition, as surfactants, fluorine-based surfactants,
Other surfactants may be mentioned.

[For production]

In the method for surface treatment of an inner layer base material for a multilayer copper-clad laminate of the present invention, the inner layer base material is immersed in a surface treatment liquid containing a coupling agent and a surfactant to perform surface treatment to form a surface treatment film. .

When the inner layer base material, which is the material to be treated, is immersed in a surface treatment liquid consisting of a conventional coupling treatment liquid and pulled up, the surface treatment liquid adhering to the surface of the inner layer base material may cause repellency or liquid clumps on the surface of the inner layer base material, causing the surface The surface treatment liquid does not adhere uniformly to the inner layer of the material to be treated, and a uniform surface treatment film cannot be formed. This is because the surface tension is high when the surface treatment liquid contacts the surface of the inner layer base material of the material to be treated. For this reason, in the present invention, by adding a surfactant to the conventional surface treatment liquid, the surface tension is relaxed and the surface treatment liquid is made more compatible with the inner layer base material, thereby forming a uniform surface treatment film. do.

[Embodiments of the invention]

Examples of the present invention will be described below.

Example 1 First, as the inner layer base material (1), a copper-clad laminate made of glass-covered soot epoxy resin having a total thickness of 0.60 mm and having copper foil 70 μm thick on both sides was used. First, in step 6 of patterning (a) in FIG. 2, a resist is applied to the copper foil on both sides so as to form a predetermined pattern, and patterning is performed by etching or the like to form a circuit pattern (2). After smoothing (b), washing with water (c), and drying (d) this patterned surface, a blackening treatment solution (sodium chlorite 31g#l, sodium hydroxide 15g#l/ Q, aqueous solution of trisodium phosphate 12g/Ω)
After forming an oxide film by immersing it in water at 95°C for 2 minutes,
Dry (f) for 15 minutes in an oven at 09C.

Next, as a surface treatment step (g), a coupling treatment solution (
β-(3,4 epoxycyclohexyl)ethyltrimethoxysilane 2% by weight, acetic acid 0.5% by weight, ethanol 6
A surfactant human surface treatment solution (0% by weight, 37.5% by weight of water) and 0.05% by weight of the fluorosurfactant Florado FC-430 (manufactured by 3M Co., Ltd., trade name) was added.
3) was used to fill the treatment liquid tank (4) of the surface treatment apparatus shown in Figure 1, and the inner layer substrate (4) on which the patterning and oxide film had been formed was applied.
1) was fixed with a hanging jig (not shown) and suspended and immersed in the surface treatment liquid (3).

7 Thereafter, it was air-dried at room temperature for 10 minutes, and then dried in an oven at 110° C. for 30 minutes (h) to form a surface-treated film of the coupling agent.

In the multilayer board manufacturing process (i), the J-1 base material (1) on which this surface treatment film was formed was laminated alternately with a prepreg (not shown) made of glass cloth and epoxy resin in the required number of layers, and then A multilayer copper-clad laminate was obtained by laminating copper foil on the outer layer and press-molding.

Example 2 A multilayer copper-clad laminate was obtained in the same manner as in Example 1 except that the amount of the fluorosurfactant Florard FC-430 was 0.3% by weight.

Example 3 A multilayer copper-clad laminate was obtained in the same manner as in Example 1 except that the amount of the fluorosurfactant Florard FC-430 was 0.5% by weight.

Example 4 A multilayer copper-clad laminate was obtained in the same manner as in Example 1 except that the fluorosurfactant Florard FC-430 was added in an amount of 1.0% by weight.

8 - Comparative Example 1 A multilayer copper-clad laminate was obtained in the same manner as in Example 1 using a coupling treatment liquid to which no fluorosurfactant was added.

Regarding the multilayer copper-clad laminates of Examples 1 to 4 and Comparative Example 1, the peeling force between the surface-treated copper foil and the prepreg was measured, and the appearance of the surface-treated film was examined. Table 1 shows the results.
Shown below.

Table 1 In the above examples, a fluorine-based surfactant was used as the surfactant, but its addition lowers the surface tension, prevents repellency and clumps of the surface treatment solution, and enables uniform surface treatment. Surfactants and leveling agents can be used as surfactants in the present invention = 9.

〔Effect of the invention〕

As described above, according to the present invention, by using a surface treatment liquid containing a coupling agent and a surfactant, a uniform surface treatment film can be formed on the inner layer base material surface without the need for special treatment equipment. This makes it possible to stabilize the adhesive force and improve its level, which has the effect of contributing to improving the yield and reliability of multilayer copper-clad laminates.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the surface treatment apparatus, and FIG. 2 is a system diagram showing the manufacturing process of a multilayer copper-clad laminate. In the figure, (1) is the inner layer base material, (2) is the circuit pattern, and (3) is the inner layer base material.
) is a surface treatment liquid, and (4) is a treatment liquid tank.

Claims (1)

[Claims] (1) In a method of surface-treating the surface of an oxide film of copper foil as an inner layer base material for forming a multilayer copper-clad laminate, a surface treatment solution containing 0.3 to 5% by weight of a coupling agent is added with a surfactant. An inner layer base material for a multilayer copper-clad laminate, characterized in that the inner layer base material is surface-treated using a surfactant-containing surface treatment liquid containing 0.05 to 3% by weight of a surfactant to form a surface treatment film. surface treatment method.